The principal goal of this project will be to model the significance of changes in the salivary flora, xerostomia, oropharyngeal flora, swallowing defects, and salivary of oral defence defects as risk factors for adverse dental and medical outcomes. We anticipate defining the population and assembling data from a fairly diverse elderly population. The major focus will be on older male veterans who are receiving medical care through the Veterans Administration. Initial information to be gathered under each of the other projects will be available for epidemiologic correlation through this epidemiology project. The biostatistics core will assist this project in order to discover the risk factors which are associated with each of the various medical and dental adverse outcomes. The methods will include longitudinal study of patients who are retained over a period of 2 to 5 years, recruitment of appropriate patients, coordination of patient followup and transportation for each site, scheduling of appropriate dental and medical followup, and gathering of specific information on medical outcomes. The epidemiology project will survey incoming data, make changes if needed in the pattern of recruitment of patients, follow patients' outcome over the entire 5 year period, and assess the meaning of the overall data collection. The data will include: 1) each of the dental risk factors found by the swallowing disorders project 3) the microbiological factors found by the microbiological project, 4) the gastric colonization project and 5) salivary factors noted in the oral defences projects. Outcome data to be collected will include medical illness, aspiration pneumonia, endocarditis, malnutrition, other medical odontogenic illnesses or death. In summary, the epidemiology project will be responsible for the collection of dental and medical information over the entire 5 year period, and intersection with the microbiology section, the immunologic section and the swallowing disorders section.